Patented 1-piece design; sealing collar will not come off. Capable of working on roof-pitch from 10 deg. to 60 deg. without stress on collar. Tear-away ring on collar provides options for sealing different pipe sizes and types. Larger thermoplastic base than normal NO-CALK flashings. Never needs caulking. Sealing collar rides with the pipe as it expands and contracts during temperature fluctuations. Leak-free seal. Won't rust, corrode, warp, or track; lays perfectly flat on the roof. Designed to seal all types of pipe, such as copper, cast-iron, plastic, aluminum, and galvanized.